org.python.core.packagecache

Class CachedJarsPackageManager

java.lang.Object

org.python.core.packagecache.PackageManager

org.python.core.packagecache.CachedJarsPackageManager

Direct Known Subclasses:

PathPackageManager

public abstract class CachedJarsPackageManager
extends PackageManager

Abstract package manager that gathers info about statically known classes from a set of jars and the Java runtime. This info can be cached, eventually. Off-the-shelf this class offers a local file-system based cache implementation.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CachedJarsPackageManager.JarXEntry Class of object used to represent a cache file and last modification time, internally and to outCreateCacheFile(org.python.core.packagecache.CachedJarsPackageManager.JarXEntry, boolean).

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.util.logging.Logger	logger

Fields inherited from class org.python.core.packagecache.PackageManager

topLevelPackage

Constructor Summary

Constructors

Constructor and Description
CachedJarsPackageManager()

Method Summary

Modifier and Type	Method and Description
void	addJarToPackages(java.io.File jarfile) Gathers classes info from jar specified by File jarfile.
void	addJarToPackages(java.io.File jarfile, boolean cache) Gathers package and class lists from a jar specified by a File.
void	addJarToPackages(java.net.URL jarurl) Gathers classes info from jar specified by a URL.
void	addJarToPackages(java.net.URL jarurl, boolean cache) Gathers classes info from jar specified by URL.
protected void	addModuleToPackages(java.nio.file.Path modulePath) Scan a Java module, creating package objects.
protected void	comment(java.lang.String msg, java.lang.Object... params) Comment log method - hook.
protected void	debug(java.lang.String msg, java.lang.Object... params) Debug log method - hook.
protected void	deleteCacheFile(java.lang.String cachefile) Delete (invalidated) cache file from persistent storage - hook.
protected boolean	filterByAccess(java.lang.String name, int acc) Filter class by access perms helper method - hook.
protected boolean	filterByName(java.lang.String name, boolean pkg) Filter class/pkg by name helper method - hook.
protected void	initCache() Initialise the cache by reading the index from storage, through inOpenIndex(), or by creating a new empty one.
protected java.io.DataInputStream	inOpenCacheFile(java.lang.String cachefile) Open a particular cache file for reading from persistent storage.
protected java.io.DataInputStream	inOpenIndex() Open cache index for reading from persistent storage – hook.
protected void	message(java.lang.String msg, java.lang.Object... params) Message log method - hook.
protected java.io.DataOutputStream	outCreateCacheFile(CachedJarsPackageManager.JarXEntry entry, boolean create) Create/open cache file for rewriting back to persistent storage – hook.
protected java.io.DataOutputStream	outOpenIndex() Open cache index for writing back to persistent storage – hook.
void	saveCache() Write back cache index.
protected static java.lang.String[]	splitString(java.lang.String str, int maxLength) Split up a string into several chunks based on a certain size The writeCacheFile method will use the writeUTF method on a DataOutputStream which only allows writing 64k chunks, so use this utility method to split it up
protected boolean	useCacheDir(java.io.File cachedir) Initialize off-the-shelf (default) local file-system cache implementation.
protected void	warning(java.lang.String msg, java.lang.Object... params) Warning log method - hook.

Methods inherited from class org.python.core.packagecache.PackageManager

addDirectory, addJar, addJarDir, basicDoDir, checkAccess, doDir, findClass, findClass, lookupName, makeJavaPackage, merge, notifyPackageImport, packageExists, split, split

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logger

protected static java.util.logging.Logger logger

Constructor Detail

CachedJarsPackageManager

public CachedJarsPackageManager()

Method Detail

message

protected void message(java.lang.String msg,
                       java.lang.Object... params)

Message log method - hook. This default implementation does nothing.

Parameters:

msg - message template (see java.text.MessageFormat)

params - parameters to insert

warning

protected void warning(java.lang.String msg,
                       java.lang.Object... params)

Warning log method - hook. This default implementation does nothing.

Parameters:

msg - message template (see java.text.MessageFormat)

params - parameters to insert

comment

protected void comment(java.lang.String msg,
                       java.lang.Object... params)

Comment log method - hook. This default implementation does nothing.

Parameters:

msg - message template (see java.text.MessageFormat)

params - parameters to insert

debug

protected void debug(java.lang.String msg,
                     java.lang.Object... params)

Debug log method - hook. This default implementation does nothing.

Parameters:

msg - message template (see java.text.MessageFormat)

params - parameters to insert

filterByName

protected boolean filterByName(java.lang.String name,
                               boolean pkg)

Filter class/pkg by name helper method - hook. The default implementation is used by addJarToPackages(java.net.URL) in order to filter out classes whose name contains '$' (e.g. inner classes). Should be used or overridden by derived classes too. Also to be used in PackageManager.doDir(org.python.core.PyJavaPackage, boolean, boolean).

Parameters:

name - class/pkg name

pkg - if true, name refers to a pkg

Returns:

true if name should be filtered out

filterByAccess

protected boolean filterByAccess(java.lang.String name,
                                 int acc)

Filter class by access perms helper method - hook. The default implementation is used by addJarToPackages(java.net.URL) in order to filter out non-public classes. Should be used or overridden by derived classes too. Also to be used in PackageManager.doDir(org.python.core.PyJavaPackage, boolean, boolean). Access permissions can be read with PackageManager.checkAccess(java.io.InputStream).

Parameters:

name - class name

acc - class access permissions as int

Returns:

true if name should be filtered out

addJarToPackages

public void addJarToPackages(java.net.URL jarurl)

Gathers classes info from jar specified by a URL. Eventually just using previously cached info. Eventually updated info is not cached. Persistent cache storage access goes through inOpenCacheFile() and outCreateCacheFile().

addJarToPackages

public void addJarToPackages(java.net.URL jarurl,
                             boolean cache)

Gathers classes info from jar specified by URL. Eventually just using previously cached info. Eventually updated info is (re-)cached if param cache is true. Persistent cache storage access goes through inOpenCacheFile() and outCreateCacheFile().

addJarToPackages

public void addJarToPackages(java.io.File jarfile)

Gathers classes info from jar specified by File jarfile. Eventually just using previously cached info. Eventually updated info is not cached. Persistent cache storage access goes through inOpenCacheFile() and outCreateCacheFile().

addJarToPackages

public void addJarToPackages(java.io.File jarfile,
                             boolean cache)

Gathers package and class lists from a jar specified by a File. Eventually just using previously cached info. Eventually updated info is (re-)cached if param cache is true. Persistent cache storage access goes through inOpenCacheFile() and outCreateCacheFile().

addModuleToPackages

protected void addModuleToPackages(java.nio.file.Path modulePath)

Scan a Java module, creating package objects.

splitString

protected static java.lang.String[] splitString(java.lang.String str,
                                                int maxLength)

Split up a string into several chunks based on a certain size The writeCacheFile method will use the writeUTF method on a DataOutputStream which only allows writing 64k chunks, so use this utility method to split it up

Parameters:

str - - The string to split up into chunks

maxLength - - The max size a string should be

Returns:

- An array of strings, each of which will not be larger than maxLength

initCache

protected void initCache()

Initialise the cache by reading the index from storage, through inOpenIndex(), or by creating a new empty one.

saveCache

public void saveCache()

Write back cache index. The index is a mapping from each source of class definitions to the file where the cache for that source is held. This list is accessed through outOpenIndex().

inOpenIndex

protected java.io.DataInputStream inOpenIndex()
                                       throws java.io.IOException

Open cache index for reading from persistent storage – hook. Must Return null if this is absent. This default implementation is part of the off-the-shelf local file-system cache implementation. Can be overridden.

Throws:

java.io.IOException

outOpenIndex

protected java.io.DataOutputStream outOpenIndex()
                                         throws java.io.IOException

Open cache index for writing back to persistent storage – hook. This default implementation is part of the off-the-shelf local file-system cache implementation. Can be overridden.

Throws:

java.io.IOException

inOpenCacheFile

protected java.io.DataInputStream inOpenCacheFile(java.lang.String cachefile)
                                           throws java.io.IOException

Open a particular cache file for reading from persistent storage. This default implementation is part of the off-the-shelf local file-system cache implementation. Can be overridden.

Throws:

java.io.IOException

deleteCacheFile

protected void deleteCacheFile(java.lang.String cachefile)

Delete (invalidated) cache file from persistent storage - hook. This default implementation is part of the off-the-shelf local file-system cache implementation. Can be overridden.

outCreateCacheFile

protected java.io.DataOutputStream outCreateCacheFile(CachedJarsPackageManager.JarXEntry entry,
                                                      boolean create)
                                               throws java.io.IOException

Create/open cache file for rewriting back to persistent storage – hook. If create is false, the cache file is supposed to exist at entry.cachefile and will be opened for rewriting. If create is true, entry.cachefile is the base name (e.g. JAR or module name) for a cache to be created, and the full name will be put in entry.cachefile on exit. This default implementation is part of the off-the-shelf local file-system cache implementation. It may be overridden to provide a different cache medium and use of entry.cachefile.

Parameters:

entry - cache file description

create - new or use existing file named in entry.cachefile

Returns:

stream on which to represent the package to class-list textually

Throws:

java.io.IOException

useCacheDir

protected boolean useCacheDir(java.io.File cachedir)

Initialize off-the-shelf (default) local file-system cache implementation. Must be called before initCache(). cachedir is the cache repository directory, this is eventually created. Returns true if dir works.